Abstract:
Pleurotus ostreatus is a commercially cultivated edible mushroom in Sri Lanka. However,
the morphology of P. ostreatus can vary with environmental conditions, and with substrate,
and techniques used for the cultivation. Cultivation in Sri Lanka, which is done over a range
of climatic zones, would certainly result in region-specific morphological variations, but
studies investigating such variations within Sri Lanka are extremely rare. This study aimed
to examine macroscopic, microscopic, and culture characteristics of P. ostreatus strains
collected from diverse agro-climatic regions of Sri Lanka. Twenty P. ostreatus samples,
collected approximately four days after pinhead formation, were obtained from farmers
related to the Mushroom Development and Training Centre- Rathmalana, In-service
Training Institute- Gannoruwa, and District Agriculture Training Centre- Jaffna, Sri Lanka
and analysed for macroscopic features, i.e.pileus, lamellae, stipe, and microscopic features,
i.e spore dimensions, along with culture characteristics on Potatoes Dextrose Agar media.
Principal Component Analysis (PCA) in IBM SPSS Statistics (version 26) was used to assess
the quantitative morphological variations among the samples. Cap diameter and stipe length
showed the greatest quantitative variability, while spore dimensions and stipe thickness
remained relatively constant. Most isolates exhibited fan-shaped caps, wavy margins,
creamy-white coloration, eccentric stipe attachment, and decurrent gills. Culture features
were largely uniform, with fluffy to cottony white mycelium. The PCA analysis revealed
four isolates, collected from Kurunegala, Jaffna, Thalathuoya, and In-service Training
Institute Gannoruwa, as exhibiting the greatest morphological variability. The findings of
the study confirm morphological variation among P. ostreatus isolates in Sri Lanka, likely
influenced by regional cultivation conditions. Documenting these characteristics can
enhance strain identification and classification, i.e. identifying high-yielding, fast-growing,
and stress-tolerant strains at the local level, provide a foundation for ensuring uniform
commercial production, and be a platform for the choice of better strains.
